- The Os01g0177900 gene product is an ABC-2 type transporter domain containing protein, predicted to participate in the transport of secondary metabolites. It is involved in various plant-pathogen interactions, and may also contribute to the transport of signalling molecules and the secretion of volatiles.
- One of these 10 genes encoded an OsABCG31 transporter and so was taken as the candidate for Eibi1. The sequence of the wild-type and mutant alleles revealed a single nucleotide difference in exon 14, predicted to alter a tryptophan codon into a TAG stop codon and thereby inducing a probable loss of function.
- Characterization of both barley and rice alleles indicated that the ABCG31 gene encoding a full ABCG transporter is involved in the formation of a functional cuticle. EIBI1 and its rice ortholog OsABCG31 may play additional roles in plant development.
- Two independent transposon Oryza sativa 17 (Tos17) events within OsABCG31 (osabcg31.b and osabcg31.c) were identified (Fig. 1 E–G), and the association between genotype and leaf water retention was tested.
- Loss-of-function mutants in both wild barley and rice are less able to retain leaf water than their respective wild types. However, shoot development was compromised much more heavily in the rice mutants than in wild barley mutants. The rice mutants attained a plant height of just 3–8 cm and did not develop beyond the four- to five-leaf stage; whereas the two barley mutants attained a height of about two-thirds that of the wild type and were able to complete their life cycle through to maturity.
- The two mutants were both highly sensitive to drought stress (as represented by osabcg31.b in Fig. 2 H), and their leaves, along with those of the two wild barley eibi1 mutants, were readily stained by toluidine blue, similar to Arabidopsis plants having defective cuticle.
- Leaf permeability is much more increased in hvabcg31 and osabcg31 than in atabcg32, indicating the importance of ABCG31 in monocot leaf water retention.
- The sequences of the wheat ESTs CJ579262, CD887967 and CD902914 share homology with the rice sequences Os01g0177900, Os01g0177200 and Os01g0176500, respectively.
- Homologs of EIBI1 were found in rice(OsABCG31), Arabidopsis(AtABCG32), Selaginella moellendorffii (Smo412699), Physcomitrella patens(Pp1s375_5V6.1), and Volvox carteri (Vca 40167). The monocot rice and the dicot Arabidopsis shared 92% and 71% sequence identities with EIBI1, respectively, indicating the conservation of EIBI1 in monocot and dicot plants(Figure 2).
Members of the diverse and ubiquitous family of ATP-binding cassette (ABC) proteins are involved in the transmembrane transport of various molecules. ABC subfamily G (ABCG) includes both white-brown complex (WBC) half transporters and pleiotropic drug resistance (PDR) full transporters. ABCG full transporters are thought to be specific to plants and fungi, where they participate in defense against pathogens and in resistance to cadmium, antimicrobial terpenoids, and auxinic compounds.
Labs working on this gene
- Laboratory of Plant Stress Ecophysiology and Biotechnology, Cold and Arid Regions Environmental and Engineering Institute, Chinese Academy of Sciences,Lanzhou 730000, China
- National Institute of Agrobiological Sciences, Tsukuba, Ibaraki 305-8602, Japan
- Institute of Plant Science and Resources, Okayama University, Kurashiki 710-0046, Japan
- Department of Plant Molecular Biology, University of Lausanne, CH-1015 Lausanne, Switzerland
- Shaanxi Key Laboratory of Molecular Biology for Agriculture, College of Agronomy, Northwest Agriculture and Forestry University, Yangling 712100, China
- Institute of Evolution, University of Haifa, Mount Carmel, Haifa 31905, Israel
- GuoXiong C, Pourkheirandish M, Sameri M, et al. Genetic targeting of candidate genes for drought sensitive gene eibi1 of wild barley (Hordeum spontaneum)[C]//Breeding science. Japanese Society of Breeding, 2009, 59(5): 637-644.
- Chen G, Komatsuda T, Ma J F, et al. An ATP-binding cassette subfamily G full transporter is essential for the retention of leaf water in both wild barley and rice[J]. Proceedings of the National Academy of Sciences, 2011, 108(30): 12354-12359.
- Tanaka T, Tanaka H, Machida C, et al. A new method for rapid visualization of defects in leaf cuticle reveals five intrinsic patterns of surface defects in Arabidopsis[J]. The Plant Journal, 2004, 37(1): 139-146.
- Bessire M, Chassot C, Jacquat A C, et al. A permeable cuticle in Arabidopsis leads to a strong resistance to Botrytis cinerea[J]. The EMBO Journal, 2007, 26(8): 2158-2168.
- Kang J, Hwang J U, Lee M, et al. PDR-type ABC transporter mediates cellular uptake of the phytohormone abscisic acid[J]. Proceedings of the National Academy of sciences, 2010, 107(5): 2355-2360.
- Pighin J A, Zheng H, Balakshin L J, et al. Plant cuticular lipid export requires an ABC transporter[J]. Science, 2004, 306(5696): 702-704.
- Verrier P J, Bird D, Burla B, et al. Plant ABC proteins–a unified nomenclature and updated inventory[J]. Trends in plant science, 2008, 13(4): 151-159.
- Kim D Y, Bovet L, Maeshima M, et al. The ABC transporter AtPDR8 is a cadmium extrusion pump conferring heavy metal resistance[J]. The Plant Journal, 2007, 50(2): 207-218.